function s1_goto_dir(){
cd "$1"
}
function s2_touch_empty_file_with_given_name(){
touch "$1"
}
function s3_make_directories(){
mkdir -p ./projects/{git/,backup}
}
function s4_create_6_files(){
touch ./projects/linux{1,2}_{centos,redhat,c_programming}

}
function s5_make_directories_in_git(){
mkdir ./projects/git/linux{1,2}
}
function s6_move_files_to_dir_1_or_2(){
mv ./projects/linux1* ./projects/git/linux1 && mv ./projects/linux2* ./projects/git/linux2

}
function s7_create_package_and_compress(){
 tar -czvf ./projects/backup/git.tar.gz ./projects/git
}
function s8_delete_dir_git(){
rm -rf ./projects/git
}
function s9_recover_from_git_tar_gz_backup(){
tar -zxvf ./projects/backup/git.tar.gz ./projects/
}
function s10_create_package_and_compress(){
tar -jcvf ./projects/backup/git.tar.bz2 ./projects/git
}
function s11_find_and_sort_alphabetically_all_created_files_and_dirs(){
find ./projects | sort
}
function s12_get_next_15_minutes_boundary(){
courrent_timestamp=$(date +%s)
rounded_timestamp=$(( (current_time + 750) /900*900))
current_timestamp=$(date +%s)
interval_start_timestamp=$(( (current_timestamp /900) *900))
next_interval_timestamp=$(( interval_start_timestamp + 900))
next_15min_boundary=$(date -d @"$next_interval_timestamp" +%Y-%m-%d_%H:%M:%S)
echo "$next_15min_boundary"
}
